1. Field of the Invention
The present invention relates to a head lamp for an automotive vehicle with a movable reflector in which a reflector having a light source mounted thereon is tiltably supported with respect to the lamp body by way of an aiming mechanism. Further, more specifically, the present invention relates to a head lamp for an automotive vehicle wherein an aiming mechanism includes an aiming screw having a rotatably supported portion which rotatably supports the aiming screw in a screw insertion hole formed in a body of the head lamp.
2. Related Art
Conventionally, as shown in FIG. 12, a head lamp for an automotive vehicle includes a reflector 2 having a light source integrally mounted thereon, the reflector 2 being supported on a front side of a lamp body 1 by a ball joint as a fulcrum of tilting movement. Further, the conventional head lamp includes an aiming mechanism having two nut members, as movable fulcrums, respectively engaged with two aiming screws so as to move the reflector forward and backward in the axial direction.
In other words, an aiming screw 4 is rotatably supported in a screw insertion hole 1a formed on the lamp body 1, and a nut member 5 mounted to the reflector 2 is engaged with a threaded portion 4a of the aiming screw 4. Rotation of the aiming screw 4 moves the nut member 5 forward and backward along the axis of the aiming screw 4 so that the reflector 2 tilts about a tilting axis extending between the ball joint and the nut member engaged with the other aiming screw, whereby the optical axis of the lamp can be adjusted.
The aiming screw 4 is made of metal and is provided with a cap gear 7 integrally formed at the rear end thereof, so that the aiming screw 4 can be rotated by a driver D. The aiming screw 4 is inserted into the screw insertion hole la from the back of the lamp body 1, and is resiliently supported and axially fixed by a push-on-fixture 8.
An O-ring 9, used as a sealing member, is fitted in the screw insertion hole la and engages the aiming screw 4 so as to make the connection, between the aiming screw 4 and the screw insertion hole 1a, watertight.
However, in the related art, the O-ring 9 for establishing watertightness between the aiming screw 4 and the insertion hole 1a, and the push-on-fixture 8 for axially fixing the aiming screw 4 in the forward and backward directions, make assembly of the aiming mechanism troublesome. Further, the conventional aiming mechanism is complex, and includes a relatively large number of components.
Since the O-ring is generally made of rubber, and tends to deteriorate when exposed to water for a long time, the conventional design is disadvantageous in that watertightness, at the portion between the aiming screw 4 and the insertion hole 1a, is degraded with years of use.
In light of the above-described problems of the related art, it is an object of the present invention to provide a head lamp for an automotive vehicle with a movable reflector in which watertightness, between the aiming screw and the screw insertion hole, is ensured without using an O-ring or other similar rubber members.
In order to achieve the above and other objects and advantages, a head lamp for an automotive vehicle with a movable reflector according to a first aspect of the present invention includes:
a container-shaped lamp body having a screw insertion hole, wherein the screw insertion hole includes a tubular portion formed integrally with the lamp body, wherein the tubular portion passes through and extends forward of the lamp body, and further wherein the tubular portion is constructed in such a manner that the portion extending forward is divided into a plurality of swinging strips each of which is resiliently deformable in the radial direction of the tubular portion, each of the swinging strips including a hooking portion formed on a forward portion thereof;
a reflector with a light source mounted thereon; and
an aiming mechanism interposed between the lamp body and the reflector for supporting the reflector so that the reflector is tiltable with respect to the lamp body, the aiming mechanism including an aiming screw rotatably supported in the screw insertion hole, the aiming screw including a recessed engaging portion, the recessed engaging portion being engaged with the hooking portions of the swinging strips to thereby retain the aiming screw in the screw insertion hole, wherein the reflector is tilted by rotation of the aiming screw, wherein the aiming screw further includes:
a rotatably supported portion supported by the screw insertion hole, the rotatably supported portion including a forward portion and a rearward portion, wherein the rotatably supported portion is formed of synthetic resin,
a male screw portion formed on the forward portion of the rotatably supported portion,
a gear portion, formed on the rearward portion of the rotatably supported portion, to which rotational operating power is transmitted,
wherein the rotatably supported portion, the male screw portion, and the gear portion are unitarily formed with each other, and
a first skirt-type resilient watertight rib in pressurized-contact, and sliding-contact, with the periphery of the screw insertion hole.
When the aiming screw is inserted into the screw insertion hole from outside of the lamp body, the divided swinging strips, constituting the end of the forward extending tubular portion, are pressed by the rotatably supported portion so that they are resiliently deformed radially outwardly. The rotatably supported portion thus penetrates the tubular portion, and the hooking portion of the divided swinging strips then engages with the recessed engaging portion on the aiming screw. Further, the skirt type resilient rib comes in contact with a peripheral portion of the screw insertion hole, so that the aiming screw is axially fixed with respect to the screw insertion hole.
The skirt type resilient rib is brought into pressurized contact and sliding contact with the screw insertion hole to prevent water from coming between the peripheral portion of the screw insertion hole on the rear side of the lamp body and the rotatably supported portion of the aiming screw. Further, the skirt type resilient rib resiliently supports the aiming screw in the forward and backward directions.
Since both the watertight rib and the lamp body are formed of synthetic resin, sliding movement therebetween is ensured, whereby contact therebetween does not prevent rotation of the aiming screw. Further, the watertight rib is formed of synthetic resin and, therefore, better resists deterioration by water than does the rubber O-ring.
The second aspect of the present invention is a head lamp for an automotive vehicle with a movable reflector as is set forth in the first aspect of the invention, and which is further characterized in that the tubular portion penetrates the lamp body in the forward and backward directions, and extends from the lamp body in the forward and backward directions, the gear portion is composed of a cap gear having teeth at a front portion thereof, and the watertight rib comes into pressurized-contact, and sliding contact, with the backward extension of the tubular portion.
Because the screw insertion hole is long, extending in both the forward and backward directions, the aiming screw may be held without rattle and watertightness is improved.
The tip portion of a driver, disposed along the lamp body for rotating the aiming screw, comes into contact with the backward extension of the tubular portion so that the teeth of the driver engage with the teeth of the gear portion. In other words, the backward extension of the tubular portion serves as a guide member for maintaining the teeth of the driver in engagement with the teeth of the gear portion.
The third aspect of the present invention is a head lamp for an automotive vehicle with a movable reflector as is set forth in either the first or second aspect, and which is further characterized in that a second resilient watertight rib having a ring shape is formed integrally with the rotatably supported portion of the aiming screw. The second resilient watertight rib is in sliding contact with the inner surface of said screw insertion hole.
The second ring-shaped resilient watertight rib is maintained in pressurized-contact with the inner peripheral surface of the screw insertion hole to ensure watertightness between the rotatably supported portion of the aiming screw and the screw insertion hole.
Since the second resilient watertight rib is made of synthetic resin and is resilient and flexible, when the rotatably supported portion of the aiming screw is inserted into the screw insertion hole, the second watertight rib becomes resiliently deformed. Because the second resilient watertight rib resiliently deforms, it does not interfere with the assembly of the aiming screw, and does not interfere with the rotational movement of the aiming screw.
Because the second watertight rib is made of synthetic resin, it is better resistant to deterioration by water than is the rubber O-ring.
The fourth aspect of the present invention is a head lamp for an automotive vehicle with a movable reflector as is set forth any of the first to the third aspects, and is further characterized in that a portion of the aiming screw, from the rotatably supported portion to the rearward portion including the gear portion, is formed of synthetic resin, and the aiming screw further includes a metallic screw body on which the male screw portion is formed, wherein the rotatably supported portion is integrally molded to the metallic screw body.
Because the area of the male screw portion supporting the reflector in a cantilever manner is constituted of a metal screw body, the aiming screw can resist deformation. Further, because the area other than the screw body is formed of synthetic resin, the weight of the aiming screw is reduced.
In the fifth aspect of the invention, a head lamp for an automotive vehicle with a movable reflector is as set forth in any one of the first to third aspects, and is further characterized in that the aiming screw includes a gear integrated screw body of metal, the gear integrated screw body having a rear end and a front end, wherein the gear portion is unitarily formed on the gear-integrated-screw-body rear end, and the male screw portion is unitarily formed on the gear-integratedscrew-body front end, and further wherein the rotatably supported portion of synthetic resin is integrally molded to the gear integrated screw body.
In the fifth aspect of the present invention, the area for supporting the reflector in a cantilever manner, and a gear portion susceptible to damage by engaging with the teeth of the driver, are formed integrally as a metallic screw body. With such a construction, the shaft portion of the aiming screw is resistant to deformation, and the teeth of the gear are resistant to wear and damage.
In the sixth aspect of the present invention, a head lamp for an automotive vehicle with a movable reflector is as set forth in any one of the first to third aspects of the invention, and is further characterized in that the entire aiming screwxe2x80x94including the male screw portion, the rotatably supported portion, and the gear portionxe2x80x94monolithically formed of synthetic resin.
Because the entire aiming screw is formed of synthetic resin, it is light-weight.
In the seventh aspect of the present invention, a head lamp for an automotive vehicle with a movable reflector is as set forth in any one of the first to the third aspects, and is further characterized in that the rotatably supported portion includes a gear mounting portion projecting from and integrally formed on the rotatably-supported-portion rearward portion, the gear mounting portion including a peg-in-recess mounting mechanism, and the gear portion is mounted to the gear mounting portion by engaging the peg-in-recess so as to constitute a single unit.
According to the seventh aspect of the present invention, it is possible first to mount the aiming screw into the screw insertion hole, and then to mount a gear portion to the aiming screw so that they form a single unit, thereby facilitating assembly of the headlamp. Alternatively, according to this aspect of the present invention, it is possible to mount the gear portion to the rotatably supported portion first, so that they form a single unit, and then to attach such unit to the screw insertion hole.